Griseusin D, a new pyranonaphthoquinone derivative from a alkaphilic Nocardiopsis sp.

A new pyranonaphthoquinone antibiotic, griseusin D (1) was isolated from the cultural fluid of the alkaphilic Nocardiopsis sp. The structure was determined as 5'-one-4-hydroxy-12-methoxygriseusin by spectroscopic methods, comparison with reported data and single-crystal X-ray analysis. 1 displayed strong cytotoxicity against human leukemia cells (HL60) and modest cytotoxicity against human lung adenocarcinoma cell lines (AGZY) with IC50 values of 0.23 and 19.6 mu g/ml, respectively. It also exhibited weak antifungal activity against Alternaria alternate with MIC of 140 mu g/ml.